I'm running an Ubuntu 16.04 LTS box and trying to get a second NIC up on it. Here is the /etc/network/interfaces config:
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
#nic1
auto et6543
iface et6543 inet static
address 10.16.15.100
netmask 255.255.255.0
gateway 10.16.15.1
dns-nameservers 10.16.15.141
dns-domain example.ext
#nic2
auto et1234
iface et1234 inet static
address 10.16.16.100
netmask 255.255.255.0
gateway 10.16.16.1
dns-nameservers 10.16.15.141
dns-domain example.ext
When I add the second nic information, I get failures when I try to restart the networking service... The ifconfig shows the correct network information, but is unreachable on the network from the switch just above the server. I have a feeling the errors are contributing to this.
Errors are:
error resolving pool ntp.ubuntu.com: Temporary failure in name resolution (-3) admin : unable to resolve host webserver1 admin : problem with defaults entries ; TTY=pts/1 ; PWD=/ ;